SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0292d98b1bbc01807f6eb8ae2560f6348b2ec163d598828c879af787ef360fb9' 
  AND token = 'hiJoUfL6kiIaFoF5EsOc8wn5NSKMrhfItGABkEkNPBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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