SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f45742a30c03fa78beeaf8f53c2bc503d48dceeca7559601b36e51d2dd2715b5' 
  AND token = 'znM9QdbGV6hiB45vvu7kZcO3Smgv7vJWyhZJAKIOnIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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