SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2fd69098633c2bf7739da5ef90868f85bade65cc0b07f3f1c4bccff87732fc1' 
  AND token = 'SHQiVpY+KBGAdKHhkwXf35GzB9izv7G/SkiblX0LeHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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