SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb9c62aae778cbeda1b7534ba0a1bea8f651f59ebd09cb59c78bbcb353592f15' 
  AND token = 'ubH6ZAH/qUSA/EJ1HTXXPhCFABKCbp3VxR4sba3R3gw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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