SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79c49a0716bd027ce5b960baab7c9764f31555784de37d638200fdb13cd516ad' 
  AND token = 'RCj/RRwaW2+yR/JTJlRxOjFCcDX+TySR60HVj0Ihis0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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