SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e5d5d9231c3ae6e0f6dd3231bb0d0db0d6835e2f3d188cbabfa76f62ab54914b' 
  AND token = '4dUtZJzJ/ngDvl6oO+2JoC1fXEuC8Y9BjTCgLetHHG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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