SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '785f6dc02897f7201b2b71d7635925bb77a5d0908266d625030543233533986c' 
  AND token = 'xhQlwnwrzoGNKfEzdOZuujf6+Nf27c+dGBSJT3um6BU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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