SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db1ffc7cabe2011700fdf6ccebbe39d7a51e579c5c9cc730a57638431c0080d4' 
  AND token = 'Ovr+1Ncc+AVzwlF+txh/spcGuppbDRglsQm0cR0Dknc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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