SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c399f5216d6efab984b9783ac80655bcb1783e68d42ec3803b947d3720ef6f1' 
  AND token = 'xClX9lB+sSBeZmv67P0TUi3uYVFMHIQPJp4HeCgyOK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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