SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ecbe99debd6531dced2fc0b94059c720512bd8fd6a8009a0540da5f57e1c930' 
  AND token = 'QrCdhM4vrt3hjb9hH5CHdVAOvqQkNUqKFp3NC+SDCB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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