SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e9e7d938a513599bca670650a5c063dc8a31ce6726a55bfd883dad129793865' 
  AND token = 'QNWlu0cyoyqP5AlYbG+5bT5IN2jbvGrh+f67XNnCRL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}