SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7720c30e1c48dbc556919438b2bf88ee62921b757e93909a8b6371aa3de5990f' 
  AND token = 'FZapp117bA9HGcD91gxtPZdmccRqjGxAUfbaMgzl7kM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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