SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6051b359d1cb427cc4bea077b7b4b887f62ed846424e57378b4bc7ce00bc00fe' 
  AND token = 'KSyQ39dDdaBOLi7L+3PAjGpFNg7fVRStdDmNHliupKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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