SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d1b4e23b8df1113366affff3f6b9130b1388c084cffdf3ec1bc2e9f3e3bbb99' 
  AND token = 'VYvxiWuro8izwycaVTQimpmIp8ATLTSJHHPMobCeHyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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