SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e1cab9895fc2fa67f1dec66696596c20dd87ccfcdb74fea3be016a55ef657d5' 
  AND token = 'Q1X2JSp4+xu5jllkopkrooHJkgZFpexkJ81rofuTkJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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