SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9154df3fd4d7d7efa7dda62de2599c27a256f6f4bc4fd07b1775710c21a13dab' 
  AND token = 'rX5fSAmoc+mfMmyIxrCFOK8/dSdNlxolMgT2N/12cMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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