SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e771be66c64aa0aff7cb5ce82dff6f1be7d0d37510ad6fe0221f51049c740eb' 
  AND token = 'U200h1mcSuzAaMNlE8cpfalhCtvz/bbmFHeWAMONTAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}