SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92639ffb22ac85ea5a8faaa2e2fb4d0846a95bf42c3c988850b1b9e0c03afd3f' 
  AND token = '13Mg2J5Jf2p2NTOR4G+85I89wAGB7hJksdyV2Ij5TkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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