SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94580208b6dac0ac424e6742ac33afa662ec695667579596d0478aebeccf8320' 
  AND token = 'hcl6rmhduKRph1VkVRqaLBmHvOKB28FmTKMVMzgu5pA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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