SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '593ded940e3f7c3486721c8f7fa56247aebfc1a09e8b50bf649cdba6a05b82c3' 
  AND token = 'gWst7eRF1sQU1A3kVJmuR/iBjgqzR+gzoWkgiZ89t5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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