SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92cfd0454b9bc118b7b7f961d587bad669c4c7938be85d24dcad9a530a206191' 
  AND token = 't/RpEF5Q9q57jk+YHDaYX8frg0x5TCvWL1qiNJG+qWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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