SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fda40e8ccb43c53f3ad4bd97da005430e262c18f6e8e32be99151d9a99aff703' 
  AND token = 'x65av8tVUqx8T24FhPj+qXv/yRhgzJZFWvvOCZFCFjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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