SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e5d20abbce9bd0cac6a2d6e0da5edf3ebcff86fc16e2c749307e42c9d76c4de' 
  AND token = '5A167j76swSITCZyidgnkRCGepukVvVrubYT27geIqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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