SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '898b0361919fb2ae0b2ea28b2d147ff55ae1656f380e80cbb2cad57add9ac1e3' 
  AND token = '3yf8hEy04vojIGp5LhAzYg7EP6+ZAYfZJFX/9XKCz/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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