SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a11984e2cd55e9237830d3294f44af68bf23bab2bd5d897cec95da1eda8ef58' 
  AND token = 'VLpAVP7SEVOONygOOpriMcP8klxHHa3WK0slcIFDg7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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