SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6118cf24b7d6a8c796cfa37f65624108fceb211f5b3b244ca44fff7688692fb7' 
  AND token = 'CiJZoMa2U9K3rjmaHi1605D1NiYFKaeJF3Ghso7xuIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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