SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1d7b4e626b85a6bab21eec09fe3d4c4e9ecda8dd0b734d7bf7021fe7f6f0626' 
  AND token = 'La85puku/Y+iya2rk240kKYkiRa2upliysywpU6Izxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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