SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4503bc54ad07721fb4796fc26c532539cf4357a5aa83e76676ec9555f04b4e52' 
  AND token = 'bnmi7xnPXz/zQbCNsQYWpJLzRupwjvIpIzr+jeZuSzw=' 
  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"
    }
  }
}