SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '734c166013b128aa025e685f9464847ff27e38b59fea37ae9e2e59d63c83b3d1' 
  AND token = 'DSmYsoErJZw378Hg2/cITuvxv/2WuE+N30jZuojSNzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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