SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99a11b5f4370afeecdd29632bd78fd9617fdf3be44752249df043f69a02b4391' 
  AND token = '4dFaC7kCjZ95W85XwUIm2WqVT9yzWo9yZqreF3JEUFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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