SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '59459ccfa6de29185cd91ba320374f479a4a6400ef0b373e1296d16317b33dc7' 
  AND token = 'bU/WEDfhMKhb5XxOWtlY+eu/s+1rY2mG8tFxBdY00q4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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