SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79062c3cf75c44e4c81889f47f5ca65e51f23df97b829d03f16d6564acc4c201' 
  AND token = 'YGunbTAsmiIqBQtm0HrSTZN/tuQKVnJ6tFEMJxy83Vw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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