SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3ffe7945c0b73657622d3a0ad25873337449de7db401c3fca7548f7b8a1528e' 
  AND token = 'o24ueEUoxKhExDBmzLK8SW82Av92ZF1GnOjBVFrbHjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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