SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18febfc6fa8e9e983716f7505d76d460c1e65ad5b454afd2b76e0ffcb200a65c' 
  AND token = 'rFt+vVrqC+voKhAHoRN1OOI771rfijzBccnlri+RKf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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