SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fab71a532d9f925435ba1a5b78ce154d4fe27d91a764b6ea74217e4ebf20fc9b' 
  AND token = 'UkrOXOK71/UXSiy2NAVJEAin5vZ2u4WdAeVRTJmC9iY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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