SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10d48105d7c7364062b313acd3352b1b6eb2344f2e6141cc6c459edd8f791667' 
  AND token = 'inhUCarEXUE9mhiJRLTQnp3e3De5HCkLINtuDabTVxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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