SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aa5bbd2bbdf6fb0693869f82a2e27cedbdc97d8238d47aa5fa2c49f4e3773b9' 
  AND token = 'zXfhbFlmdIK12qKIsZvZGe1R7YpM9A+AXldBCO+9yws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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