SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c015c6d67e4b2a65d208d783b173fb3e9b35498f41fee1967459af69f8106db' 
  AND token = 'W2M0IIDGV9KJZ+HPwgTReXyFHprTr8eObwzYZtBckxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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