SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '58a94cb7623624827fd650b9a529997b6cf99da165b75fe8edc6143c906e1de3' 
  AND token = 'LURjg+eKbCHCQ1tHE9/Mvo61i9fCaMGspeQR5zVaaM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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