SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96eee8ae06e286c1c26f0f327cf148f80bb71af4c1540328e5ad2a91dabf279f' 
  AND token = 'aj247owRXjgeZ3N6rCU5Zgr4WhCnATWfRnSsjTHokxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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