SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aac18fb402813886701699d7d8c978282f3a5c37d7ac5965dd223f0f805c9964' 
  AND token = 'BljjToKRAeLIFcWp+NluHpKucZDBjS1M3QXbARkvUs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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