SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26ad00df34b0a222aa4700020046e67b184de49ffbb5a45500e45c6fd92f430a' 
  AND token = 'XVSPIrlklITBm6kkVjiZNlrEelKNKg6JAWT1NW1jpUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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