SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e38df0466af274e6aeba3a009c917904fe57b8a00cdc54b85e91ddc6f6157ff' 
  AND token = 'e8lXuG/thDpmQQmjxMATpzyB1SQJajuxlQxlYZ5HsOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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