SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a585d749b1de82dee35ceec643c997153ca2c5ecd5dbba28b646662d7f2f757' 
  AND token = 'Bo4vFHpEVBKSynOnIuOK+qMIYrI0n1VKawhVl/x74gA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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