SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '915ec49e34ecd3e13c1b1c53969cda2d60032950a5b88a6bc86c5289ef6dce88' 
  AND token = 'qIpNzIvPqj5UNT6wwR2r/o/NANjMeeyHqcTmDdFYMuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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