SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecd2ad76fc3fc7285db9421ce08e4a6aaf3f6629055052a84621c1578951a3e5' 
  AND token = '7mgt26sHURWmPZgmSu9q4ZzbInK6lLakX3bvYRLLQQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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