SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '009b8577578149423ccb48c338f9475338bd72bd047c0f7ff96bf48ea755eeba' 
  AND token = '9uIVkVhoSgYTavW+DDGLjdAHGQifKiJVQi40y7DYIgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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