SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc03692adf9f1ca0bcb3066406ea6873ff301448cecbe73e8d9d2bce2d0f263c' 
  AND token = 'RAlKIIGewC1rsRMKgChA2HW/0wmSNYv9nZcgluM7lTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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