SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a2c93401aa870df3b1cf31d5204fe5c4ffca962291f1dda64c17dd2f9a44113' 
  AND token = 'O6SYn9SmSqvQc7fqUHwdKeSufp2IX4KWfztblRVEebw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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