SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8743b12f9ecf52b05e026c335f6d838f107d2c7a45a7cf386618026714afe19c' 
  AND token = 'GXR8rtKhHClkQ8iCiR+pbwbqUaolQJYtaHHz2ePBEBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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