SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575b4a20a7a31958bee6d6fec70a88135ca37c293da5169270647aacae2de8cb' 
  AND token = 'Q2iJVPo49oTC9s41kWC2DLa+y8hjEv1i00M4plpTGMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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