SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87e09fe9699f4cc430da03c6836aae257771d7ab8b671e7b938d87287f6765c4' 
  AND token = 'OSGjY29dLCQF9s4i6pP8t7H4FoFVT8mw25a2GGr53HE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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