SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc8f0dd5a832d2e736ab6b76a88c85e8fe64d63571ad7482f3780cffb45cdd04' 
  AND token = 'SeJZBpsDzXSWGi5terOlLlM/y3lu4PhjkWMnaI/ySpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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