SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f76176415f5f41f91a21271e5847f6224ad2a9b642f02ee93b6913ef32b8b7a1' 
  AND token = '1T7w5E0a5iFkZoMGdc2qKFKp2Nei0CP00fZU9fIyQng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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