SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b57e76009bdbaabeb16183ef33f42712468ad5df6a736f9a7a597531f88dd66' 
  AND token = 'PuFZ8Jh6JjtG6dC5Lp0ZPunUr6x+8mThmgoz11B4tFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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