SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99884fd8feda0849dfc9a0bb0fe57a810148179791483bb481629c6294583f24' 
  AND token = 'fYoTCrp8586pdFIzdLm0pOekB6E65ph2LfVjj1Opnwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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