SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44f3fdda2e4e0c1a76db46e6453646998de6df60cc0db99fca069588652c2782' 
  AND token = 'dXhe/F/UzPPYkAqlOP4Q1aqcv4bPd057QihukMUkp0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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