SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adee8842105e2627cd72f9cee6077e7350684b66b1db54acc6cdbdc3442c3b8e' 
  AND token = 'Nsdknc3OZZ35g58b26xtIRzBAk4gT4u2UHldULsq3Ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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