SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e1d5f8609ba8df320836cc84ad6a9ef27c64bdfc0f18e164ee595bcf59f9713' 
  AND token = 'RtxcfVLAwXi9KuTEWI7ImmU708ckvf2RfyrtiaeXjCA=' 
  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"
    }
  }
}