SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '207a673a1183c0993041e1daa98bd0eb69b3691f7a9262559bd0e4581559142b' 
  AND token = 'H+QEHCmwhjhHsDGq8fnTtlBPvjcx0GfrVmZLu5eN3Dc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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