SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61da452b9f64b91d758ac0f0402723597895561d2dbe7d41f365c2f576ecf850' 
  AND token = 'omNa/RbdtC8/MAO+P8hfjTwRuhZP/NYYrjezqDGjLBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}