SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6b7a0f048b7f0fef267d66ef9695858df04e0a01cd85fdcf3dae15ac57274d3' 
  AND token = 'MkgHHr+ycFjK/Q0Fol4YlWUhURQ5GyuofhxTvv6WwHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}