SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f2cdd4b78126bdd020a54130fc48df38bc62de784d290e2634f03805c46e42f' 
  AND token = 'P/XxnscU+GJnZliV0O+gMPkTfQOW+Ep9fhcglKdLmF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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