SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5477fcc3a52d555042e24592559656f505fb8bb2ffa11926f781f172962887e' 
  AND token = 'Zj8KONwaNjIPYcX6lpYX+FXBkLkP7hhGiBfFJub4Z2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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