SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f4cf72883136be6a5f7ae4870fa74b651eb094b84a28d57edd7daa770c0af5e' 
  AND token = 'VCXguypF2Ojmyn+5vO9lDeCQTI3BlpsZNhwPCGVIjng=' 
  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"
    }
  }
}