SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a13ebe8a31ebf3dfe72f80109b66ac88c2d4e52f04b297e0ef5995afef4b4c32' 
  AND token = 'bUFlyRdmUfXRDbczESaSR2dPJjDLK26DKUK5a8DoILY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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