SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '637106c9d860d292403a79b24c60eece09d87ba716d7aff784b11859c49ed7fe' 
  AND token = 'jknlRlSmpADr7kzl8BG+rxuIlyy4BWXVieGbZb4z4TM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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