SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63bc7f12fbd7f3669f9265c899b495519fe78a3776580c9e17f065b104232224' 
  AND token = 'eKyXbPojTqrNTFvontl20qDmd3vEOSZIbcG1jOuSoF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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