SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8e3480ee62eca87ec6d37f26f8335557cbc91ff7d4d561337c94f2bdaa90df6' 
  AND token = 'Ho7lh2Ib6y/mBWSIYGGVLrftVYY9iNnuz/0J+xPXbwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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