SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dae9c28bfcc95ed747330beb40bdba250923fda6b47bbe662cbc171e19a7890f' 
  AND token = 'bGoKxUikCQmWxpDso6snUYbdqFwisNAaaR6ezVehI1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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